Improvement in chucks and centerers



J, R. MASON.

Chucks and Centerers'.

N0. l66,538, PatentedAug.10,1875.

NITED STATES PATENT Error 'JOHN R. MASON, OF WILMINGTON, DELAWARE.

IMPROVEMENT IN CHUCKS AND CENTERERS Specification forming part of Letters Patent No. 166,538, dated August 10, 1875; application filed June 22, 1875.

A is a circular casing, with four grooves running directly central, which contain four jaws, B, each having a scroll upon its lower side, extending toward the interior of the casing. 0 is a scroll-plate, with cogs and scroll combined upon one side. The cogs are situated above the scroll upon the top edge of the plate. This plate has a bearing upon the inside of the casing A, with scroll facing the jaws B, and is turned upon the bearing by means of the key D gearing into its cogs. The key consists of a knob and pinion combined, having a bearing between said knob and pinion, and also upon the extreme end below the pinion. This key is let into a bearing upon the face of easing A. E is a plate, secured with screws into said casing, and secures the key D to its bearing. F is an arm-plate,

which is attached to the back of casing A with screws, having a circular bearing upon one end. G is a face-plate, with bearings to suit the circle of arm-plate F, having a dovetail groove running central through the plate; also a similar but lesser groove placed above, 6X-' tending central and opening into the main groove, in which is placed a small lock-plate, H. I is a sliding plate, which slides in main groove. The tool J is secured to the sliding plate by a thread, and tool K is attached to said plate by groove and feather. The lockplate H is forced into openings in sliding plate I, when tools J or K become central, by a spiral spring, L. M is a ring, secured to the face-plate G by screws, which inclosesthe circle of the arm-plate F, which produces a bearing. N is a'cap, which is attached-to the back of the face-plate G by screws. This cap can be bored and chased to suit the spindle of any lathe.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent? The combination of arm-plate F, face-plate G, lock-plate H, ring M, and sliding plate I, adapted for the use of two tools, J and K, with the scroll-chuck, all as and for the purpose specified.

JOHN R. MASON. Witnesses:

JAMES S. GRINNELL, HARRY COLEMAN. 

